Internal broaching machine



March 18, 1958 A. R. GRAD INTERNAL BROACHING MACHINE Filed Dec. 23, 1953 7 Sheets-Sheet 3 INVIIENTOR ADQLF R. GRAD l F lllll IL 9 1 we $N\ 7 W ATTORNEY March 18, 1958 A. R. GRAD INTERNAL BRO-ACHING MACHINE 7 Sheets-Sheet 4 File'd Dec. 23, 1953 FIG.6

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INVENTOR ADOLF R. GRAD March 18, 1958 A. R. GRAD 2,826,964

\ INTERNAL BROACI-IING MACHINE Filed Dec. 23 1955 7 Sheets-Sheet 6 INVENTOR ADOLF R. GRAD I6 I as r ATTORNEY March 18, 1958 A. R. GRAD INTERNAL BROACHING MACHINE 7 Sheets-Sheet 7 Filed Dec. 23, 1953 FIG.|5

gPSZ I Q G q b |NVENTOR ADOLF R. GRAD ATTQRNE Y United States Patent O 826,964 INTERNAL mos-crime MACHINE Adolf R. Grad, Milwaukee, wis assignqr, by inesne "assignmen'ts, to Detroit Broa'ch -& Ma'cliinefioinpahy, Rochester, 'Mich., incorporation of Michigan Application nec'einberzs;rssasenaiiso; 101051 2 Claims. ((21:90:33

This invention relates to broaching machines of the type havihg a statibiiary work support for supporting work to be breached, a breaching s'lide -reciprocable in a path adjacent to" the work support and haying a tool puller for engaging the leadingend or nose of ;a breach, a tool handling'slide'reciprocable'in a pathparal'lel to the path or the breaching 'slid'eand havingja socket to engage the trailing end er tail of the breach, power means for'r'eciprocatin'g the tool handlin' g'slide tomove the nose of the breach into and out of 'e'n ag'" 'en't iwith flie tool puller, and power means for 're'cipr ing the breaching slide to pull the breach through thewark and thereafter return the breach into engagement with the sdcket.

In the prior machines of that type, the pawe'r'nieans for the i001 handling slide rearranged ina stationary pbsition and th'efbroa'c'h is pulled an: of the -socket n15- media'tely after the breaching slide starts to h'i'o've on a breaching stroke. v

The present invention has as an 'dbje'ctto provide a breaching machine of the above type iii fwh'ich the trailing end of the 'broach is guided during a large piiit'bf f'the breaching stroke. 7 H

Another ob'ject is to provide a machine in which tension may be maintained upon the 'b'roaclii'hg' tool d'u'r'i'r'i'g the greater part of the broaching sedation.

Another object is to'provide such a machihe whic'his very accurate in operafien e v w e e A machine constructed according to th 'lillfsefii. invention has the advantage that'it'rn'ay be reduccdiii length when being transported and erected. v

Other objects and advantages Will appear from the description hereinafter given b f'a ni'achifie embodying the invention. I I

According to the invention in its principa'l aspect'the machine is provided wiih abl'O e1ChlIl g"S1ld 'h" guideway, the tool handling slide is recipr' I guideway, and th'epj'power means jreic i'pr ting the reel handling slideis earned 'the'tirdachirigblide. j

The invention is ekernpl ifi'ed by the breaching in chine shown diagrammatically in the accompanying drawings in which the view are astonow's';

Fig. 1 is a front elevation of'tli'e machine. u 4 I Fig. -2 is aplaifvi'ew partly iii fsfctioii 'talte'n'fdn the line 22 of Fig. '1 biit 'driafnto alarg er scalqtheYear portion of the machine being omitted. v N

Fig. 3 is 'a central vwresrseeaea taken ftl'i'fiu gh the lower part ofth'eimachiiie on'tl ie 3 oj'f' F1 '2 "Fig. 4 is a SEiiOi'l taken through the u per part bf the machine on'the line 4'-4'bfFig. 2. e 1 h Fig. 5 is "a top plan view of the tool handling-slide as indicated by the line 5--"5f6f Fig. 4'. 7

Figs. 6 and 7 antenna-retrace sections-taken, respec tively, through a tool *handl'ingso'cketa ft'ool puller which "may be used on the machineaiid Pig. 8 is a'detail view of the leading end or noseof the Broach'tobe used in connection with thetool puller shown in Fig. 7,-the views being drawn 'to alarger scale than the other views.

Fig. 9 isa diagram illustrating the hydraulic circuitof 2,826,964 Patented Mar. 18, 1958 ice 2 themachine andindicating the relative 'locations -anddunctions of certain electrical devices.

Fig. 10 is a view showing a difiierenti-al Valve-member in a position diiferent from that shown in Fig.9.

Figs. 11 and *12are views showing a'directional control valve member inpositions 'diiferent from that showh in Fig.9.

Fig. 13 is a-pentr-al vertical sectiontaken through-a tool handling-socket which may be used-when i-tisde'sired to maintain tension upon the breachingtool=during tlie broach ing operation.

Fig. 14 is a sectional v-iew taken through-apart-of -the machine in the same plane as Fig. "'4' andd-lh'istratiirg a means for opening the socket shown in Fig. '13. v

Fig. -15 is a diagram illustrating 'thejprincipal pat-ts df an electric circuit which-may be employed to cdnt-rol-tl'ie opeiationof the machine. Fig. 16 is a diagram illustrating the relations of certain switches showh in Fig. 15.

e For the purpose of illustration, the machine h'as been shown as having a frame which includes -a vertical colufim or main frame 1 having apairof spacedapa'rt front plates 2 and a sub-frame or knee 3 which is fixed at its oppdsite sides to plates 2 and has a heavy .plate or work 'support l uppirits upper end.

Each of front plates Zhas a guide bar '5 fixed thereto and je'ii'tending beyond the'inner edge thereof. Plates "2 and 5 form aguideway-for a main or a breaching-slide 6 which is adapted to be reciprocated vertically by \a hydraulic motor shown as including '-a cylinder *7-Wl1ich is rigidly seemed to frame 1 in; a vertical position, a' pisfton S'wh'ieh is fitted in cylinder 7, 'andia.piston-rod -9 which is'fi xed to piston S and is rigidly conneeted-towslide 6. As shbwn, rod 9 is extended througha-fl-ange ld'which isrermed integralwith slide 6 at the-upper end 'thereof, tlfe'p'oit'ion of rod 9 which extendsthrough -flangeilil is reduced in diameter, :and anut 1;1isthreaded'upondhe of was. The lower portionof slide 6,"wh'ieh bin-knee 3 during reciprocation 0f'S1ldC-'6,"hfl S yse'ciired theret'o a bracket 12 to whic-h one or -more tdol'pifllefr's'iiiay be attached as will presentlybe explained.

Main slide 6 has an elongated recess IS-extending into itfir'oi'n its ffon't face and a path of guidebars er: gibs I6 I ng'e'da't opposite sides 'of recess 1540 form therewithfa igiiiaeway for a tool handling or auxiliaryslide 17 which can move vertically therein relatively to slide' 6 but is prevented trom moving in any other direction.

, 'Auiiiliar'y'slide 17 is adapted to be reciprocated' relatively'fo slide6 by power means carried by slide' 6 such aspire 'or mere hydraulic motors, two beingshowii. f Ea'eh hy'd'r'aul icinotor has been shown asineludi-ng a eyli-nder 1s "w nes is formed in slide 6, 'a pistondlwhieh is fitte'd ii'rcYIifiderIS, and apiston rod 20 whic-hhasene-end flied-to piston 19 and its upper end rigidly secured to slide' 17 "at upper end thereof such -as' being fastened to a bracket 21 'which is-bolted--to the rear face of slide llatthe' iipper end thereof,

Slide '17 has a tool handling bracket =22 attadhed' to it's fmntfa'ce at or near its upper end in such amanner that it may be-adjusted vertically relatively -to slide :1'7 to aedirimodat'e btoaches of difierent lengths. For -exaifiple, 'bracket 22 maybe attached to slide 17 by bolts havihg'the heads thereof arranged in T-slots formed in slide 1 7.

Brack'etZ Z has attached thereto oneor-nrore -too1 handling sockets 23, three being shown in Fig. 1,-and bracket 12 has-an equal number of tool; pullers 24 attacked thereto. Each socket-23 is in vertical alignment with one of the toolpullers 24 and an Qpening -QKS: is

formed worlg support4 in vertical alignment with each. puller zd so that broaches canbe pulled 'compl'etely I through work arranged upon work support 4 in alignment with openings 25.

The machine may be provided with any suitable tool handlingsockets and tool pullers such as those shown in Figs. 6 and 7 which are ofsuch well known types that only enough thereof has been shown to illustrate the functions thereof.

As shown in Fig. 6, socket 23 includes a casing having a plurality of bolts 31 extending vertically therethrough for attaching it to a part of a machine. Fig. 1 indicates that sockets 23 are bolted directly to bracket 22 but in practice they are bolted to a separate plate (not shown) and the plate is bolted to bracket 22 so that the sockets may be arranged in different positions by using different plates, thereby avoiding the necessity of replacing bracket 22.

Casing 30 has a tubular bushing 32 arranged vertically therein at one end of a horizontal bore 33 which has a plunger 34, fitted. therein and urged against bushing 32 by a spring 35. Plunger 34 has a detent 36 formed upon one end thereof and extending through an opening 37 in the wall of bushing 32. Detent 36 is adapted to extend into a cannelure 38 formed in the trailing end or tail 39 of a broach 40.

The end of detent 36, the end of tail 39 and the end walls of cannelure 38 are tapered so that, when socket 23 and broach 40 are moved toward each other, tail 39 can be forced through bushing 32 to the position shown in which position detent 36 will support the weight of broach 40 and, when socket 23 and broach 40 are moved away from each other, broach 40 can be pulled out of bushing 32.-

'As shown in Fig. 7, each tool puller 24 includes a body 45. having a shank 46 by means of which it may be rigidly secure to bracket 12. Body has an axial bore 47 toreceive the nose 48 of broach 40 which has a cannelure 49 formed therein. Bore 47 is intersected by two or more transverse bores 50 each of which has a key 51 slidably fitted therein.

The parts are shown in the positions occupied when main slide 6 is in its uppermost position at which time the outer ends of keys 51 are arranged within an annular cam slot 52 formed in akey actuator 53 which is slidably fitted upon the outer peripheral surface of body 45. With slide 6 in its uppermost position, actuator 53 is held in the position shown by being in contact with an annular abutment 54 one of which is fastened to the underside of support. 4 around each of openings 25 as by means of bolt 55. I

The outer ends of keys 51 and the lower wall of cam slot 52 are tapered so that upward movement of actuator 53 relatively to body 45 will cause keys 51 to be moved radially inward. If. the nose 48 of broach 40 has previously been inserted into bore 47, the inner'ends of keys 51 will enter cannelure 49 and cam slot 52 will move above the outer ends of keys 51 and" cause keys 51 to positively lock broach 40 to puller 24. Also, the inner ends of keys, 51, the end of nose 48 and the end walls of cannelure 49 are tapered so that, when actuator 53 is in the position shown, keys 51 may be moved radially outward in response to movement of nose 48 into or out of bore 47. i r v Actuator ,53 is used upward by a spring 56 which reacts against a sleeve 57 threaded at its lower end upon shank46. The upper endof sleeve 57 is slidably fitted upon the outer peripheral surface of actuator 53 and an annular guard 58 is pressed upon the upper end' be manually inserted into or removed from socket 23.

With tail 39 inserted into socket 23, detent 36 will sup port the weight of the broach and then downward move- 4 meat of slide 17 relatively to slide 6 will cause the nose 48 of broach 40, to enter bore 47.

When both slides move downward, actuator 53 will move away from abutment 54 and spring 56 will raise actuator 53 relatively to body 45 which will cause actuator 53 to advance keys 51 and positively lock broach 40 to puller 24. When slides 6 and 17 move away from each other, puller 24 will pull broach 40 out of socket 23.

Referring now to Fig. 9 liquid for energizing motor 7-8 is provided by a main pump P1 which may be of 4 any suitable type but which has been indicated as being a reversible. variable displacement pump of a type which is well known and in extensive commercial use. It is deemed sufiicient to state that pump P1 has a control stem 60, two ports 61 and 62, that it is provided with a reservoir 63 containing a supply of liquid, that it is controlled by two solenoids S1 and S2 which are connected to control stem 60, that pump displacement is zero when both solenoidsare dcenergized, that solenoid S1 when energized will move control stem 60 outward which will cause pump P1 to discharge liquid through port 61 and be supplied with liquid through port 62, and that energizing solenoid S2 and deenergizing solenoid S1 will cause control stem 60 to be moved inward and pump P1 to discharge liquid through port 62 and be supplied with liquid through port 61.

Port 62 is connected to an external channel 64 and also to an internal channel 65 which extends into the liquid in reservoir 63 and has connected therein a check valve 66 which permits the pump to draw liquid from reservoir 63 but prevents the pump from discharging liquid through channel 65 into reservoir 63 except through a high pressure relief valve 67 which is connected in parallel with check valve 66.

Port 61 is connected to an external channel 68 and also to an internal channel 69 which extends into the liquid in reservoir 63 and has connected therein a check valve 70 which permits the pump to draw liquid from reservoir 63 but prevents the pump from discharging liquid through. channel v69 into reservoir 63 except through a high pressure relief valve 71 which is connected in parallel with check valve 70.

Liquid for control purposes, such as operating the displacement varying mechanism of pump P1, is supplied by a gear pump 72 which has been shown as a separate pump but which in practice is driven in unison with pump P1 and is arranged within the casing thereof. Pump 72 draws liquid from reservoir 63 and discharges it into a channel 73 one branch of which extends to a point of use of the liquid, such as the displacement varying mechanism of pump P1, and another branch of channel 73 is connected through a low pressure relief valve 74 to a channel 75 which is connected through a low pressure relief valve 76 to reservoir 63 and is also connected to channel 69 through a check valve 77 which permits liquid to flow from channel 75 into channel 69 but prevents fiow in the opposite direction. When the pumps are running, gear pump 72 will maintain in channel 75 a pressure equal to the resistance of relief valve 76 and it will maintain in channel 73 a pressure equal to the sum of the resistancesof relief valves 74 and 76..

Channel 64 has, one branch thereof connected to one port of a pilot controlled foot valve 80 which has its other port connected by a channel 81 to the lower end of cylinder 7. Foot valve 80 is of a type which is well known and in extensive commercial use. It is deemed suflicient to state that it includes a solenoid S3, that it is closed against any flow of liquid when solenoid S3 is deenergized, and that it will open at a low pressure when solenoid. S3 is energized.

Channel 68 and the other branch of channel 64 are connected to opposite ends of a bore 82 which is formed in the casing 83 of a differential valve 84 and has formed in the wall thereof a,cen ter port 8 5 and two interconnected ;.p,orts"86;-.aitd' 87' 'jwhich-are arranged "at opposite'fs'ides or pcrt 85"and are'connected to the'upp'er end ofcylim def-7 by a channel fls havingconnected theretoa pressure sWitchPSl 'whichwontrols so1e'n'oid S3. Port'f85 communicates through a low'pressure relief -valve 89 with a reservoir which has been -designated by "the reference -numerals GM -butWhich' in practice" is'ireservoir 63. Bore -82 has "-fi-tte'd therein a valve member 9fl'which has a duct'91 extending axiallyflin'to it -from' 'its lft end and then extending radially outward into communication with port85.

I The n arrangement is such --that,-when the *displacement of: pump P1 -'-is zero, piston 8' is-"sjupported"'by liquid trappedi-n cylinder 7 by foot valve 80. When pump P1 discharges liquid through prt 61,' 'thefliquid' wiH flow through channel: 68 .tothezrighteend of: diiferential valve 84 and move valve member 90 to the position shown in Fig; 10. Thenthe liquidwill' fiow throughvalve 84and channel-88 and -tend to move -piston8 downward but foot valve '80 will resist discharge of liquidfrom cylin- 'der 7 'and'thereby cause pump'rpressure" to'- rise and operate-pressure sw-itch PS1-whic-h, 'as will' prese1i'tly"be explained, will cause solenoid 83 "to be -'energize"d so that .foot valve i80 will= open 'at a lower-pressure.

Then the liquid: entering the upper end of cylinder 7 will 4cause piston 8 to move slide" 6 downwar'd add *to eject 'liquid'from\cylinder 7 5 through channel- 81mm foot: valve 180. i into: channel 64. The volume of liquid ejected'i'fromicylinder7 into channel's is -greater'than the volume":discha'rged 'by pump Pl-*dueto the displacement 0f2piston"ro1d= 9. Enough of' 'the ejected liquid to supercharge pump Pl' will'fiflow' through "channel 64'to port :62 aand' ithe remaindernf the ejected li'qui'd will flow through channel 64, difierential'Walve 84 vie' duct 9.11andr-p0rt 5 and relief valve 89 to exhaust.

W'hen pump P1 discharges liquid through port 62, somegof the liquid=will ilow through channel 64, I-move valve ;member 90 to Y the position' shown in Fig. 9 1 and create enough pressurein 'channel- 88 tooperate pressure switch PS1 and "thereby oa'use'solenoid sii to be'-energized and to adjust foot valve 80 ''so' that 'itwill open at "a lower pressure. *Then 'the-liquid discharged by pump' P1 -will flow through-"channel "64, toot-"valve 3 '80 and channel 81 to the lower end of cylinder '7 and cause-pistonS to move slide 6 upward-andto eject liquid from cylinder 7 through channel 88 and difierential valve 84 into: channel 64 where it joins the liquid "discharged by pump Pl an'd 'thereby causes' pis'ton '8 to n'rove slide 6 upward at 'hi'gh'speed.

:During1the time that' pumpll is di's'chargifig into channel 564, lliquid discharged by'gear-pu'mp 7-2 will flow throughmhannel 73, relief waive-'74, channel =75,- check valve and channel '69 into port- 61. lf' the volu'me supplied bygear pump 72 is insiitficient to ke'e'p pump P1 supplied with liquid, pump 5B1 =-will draw- -'liq'uid T from reservoir 63 through channel 69 and check valve '70.

Liquid toren'ergizing tool handling xnot'ors 18-49 is. supplied by an auxiliary pump rP-2 shown as bing supplied with liquid from a reservoir 63 but it may "be supp'liedl-from reservoir 6-3. :F1ew:of :1iquidto an'dfrom motors 18-1-19 is:controlled byalcontrol valve 95 which includes a :casing-.96 having an axial bore 97 'formed therein and .a valve member-198 tfittedzin bore 97. Valve member 98 controls communication .between an exhaust port .99, an inlet :port 100 and two :distribtiting iports 101 and 102 all .of which are formed-in *the wall of here '97.

'Valve member 98 is urged to its'c'entral 'orneutra'l position as shown in Fig. '9 by two springs 103-and 164 audit is adapted to be shifted 'in-onedire'ction or the other in response to one or the other of two solenoids S4 and 85' being energized. In order to simplify the drawing, solenoids S4 and S5 have beenshown connected directly'tojthe's'tems of valve member 98 liut"in' lrtr'actice valve member 98 is shifted by liquid supplied thereto from 'gear pump 72 under the controlfiffapilot valve and the pilot valve is shifted by ithe soleno'ids.

Discharge port 99 of valve 95is connected *to 'exhaust by a channel W5 which has beemshow'n' as being connected to opposite ends'of bore 9f7. "Inlet po'rt 100 is connected to the outlet ofpurnp 'l2' by a channelfi106 which is'also connected to exhaustthrou'gha relief'valve -107and a choke 108 which have a"p'ressure*'s'witch"PS2 connected therebetween. V

Distributing ports 101 and "102 are connected 10* oppo site ends of motors 18 19 by 'chanhels 'having flexible or extensible portions such as flexiblefftubingorslide pipes. -As shown,v port 101 is connecte'diby 'a channel 109 to the lower end of a slide 'p'ipe lltl'the upper'end of which is connectedtothe u'pp'er'en'd ofcyliiidrs 18 by a'branched channel 111 and port TOZis'cQnne'c'tedbY a channel 112, a check valve 'llfi and a'r'eliefvalve 114 which are connected inparallel"witheachfotherj a 'ch'annel 115, a slide pipe 116 and a branched channel 117 to the-lower ends of cylinders 18. Check"valve"1113 permitsliquid to flow freely'from valve 9510 "fthe lower ends of cylinders 18 but prevents liow"fromthe"lower ends of cylinders 13 to valve95 except throt'igh1'e1ief valve 114 which has sufiicient resistance to'prevent piston 1'9 and'slide 17 from descending by gravity. p

'The arrangement is such'that when 'bothfof'solenoids S4'and S5 are deenergized, 'springsfitliand 1'04 willhold valve member 93 in its neutral 'p'osition""as slidwn'inFigi9 and pump P2 will be bypassed through cha'niiel 1116, valve 95'and channel N5. When solenoid S4jis energized, it will shift valve member 98 in'tothe "positionshown' in Fig. 11 and then the liquid iseharge -b pum 'P Zwill fi'o'w through channel "1%, valve 95, channelflflkslide pipe 110 and channel 111 to the 'uppe'r ends of cylinders 18 and cause pistons 19 to move slideljfdownwardfand to'eject liquid from cylinders 18 through channel 117,

slide pipe 116, channel lllsfrelief valve 114,ch'annel 112, valve 95 and channel 1'05 to "exhaust.

. liquid discharged by "pumpP2 will flowtliiough channel 16,valve 95, channel 112, check valve113, channel 115, slide pipe 116 and channel 117 to'thelow'er "ends of cylinders 18 and cause pistons 19 to move" sli'il'e' 1711pward and to eject liquid from'cylinders 18 tliroii'gh"channel 111, slide pipe 110, channel 109 andva1v'e'i95 iiito channel 112 where it 'joins the liquid discharged by P2 so that slide 17 is moved upward by liquid acting upon an area otso-much of each piston 19 equal only to the cross-sectional area of piston rod -20'at ,a hi'gher speed than obtainable if merely tlle'oil deliver'ed by the'piimp P2 were employed.

When pistons 19 stallaga'inst'the up 'erends of cylinders '18, pump pressure will rise and cause pressure swith PS2 to open, solenoid S5 to be deenergized and'valve member as to be returned to neutral andbypasspump P2 as explained above. a 4

It haspreviously been explained that, "hen slide 17 moves downward relatively to slide 6, 'a reach carried by a socket 23 will be inserted into a tool-puller and that, when slides 6 and 17 move a wnwardtogetheg uuer 24 will fix the broach for movement with "slide 6. Socket 23 will guide the trailing "end or the breach and positively hold it in alinement with the leading eiid thereof but, if the broach is very slender, it"is very desirable 7 to maintain tension on the broach to prevent deflectio of the intermediate portion thereof.

If tension is to be maintained upon the broach during the greater part of the breaching operation, socket 23 i bracket 22 must be modified as indicated by the bracket 22 shown in Fig. 14.

As shown, socket 23 includes a casing 120 and a top plate 121 which are adapted to be fastened to bracket 22 in anyrsuitable manner. Casing 120 has a tubular bushing 122 extending therethrough to receive the tail 39 of the broach. The interior of bushing 122 communicates through an opening 123 with a chamber 124 which is ,formed in casing 120 adjacent to bushing 122 and has a locking lever 125 arranged therein and pivoted intermediate its ends upon a pin 126 carried by the side walls of chamber 124.

One end of lever 125 extends through opening 123 and is adapted to extend. into the cannelure 33 in broach tall 39. That end of lever 125 is urged downward against the bottom wall of opening 123 by a plunger 127 which is fitted in a bore 128 formed in casing 12 Plunger 127 is urged downward by a spring 129 arranged within bore 128 between plunger 127 and top plate 121. The

other end of lever 125 is engaged by one end of a trip lever 130 which is pivoted intermediate its ends upon a pin 131 carried by twotlugs 132 which are formed upon casing 120 at opposite sides ofchamber 124. The other end of lever 130 is bifurcated and has a roller 133 journaled therein upon a pin 134.

Roller 133 engages aflat cam track 135 formed upon a rod 136 which is slidable through the horizontal part of bracket 22 and through a guide 137 which is fastened to bracket 22. Rod 136 has a head 138 formed upon its upper endand normally held in contact with bracket 22 by a spring 139 arranged around rod 136 between guide 137 and a collar 140 fixed to rod 136. The lower end portion of rod 136 is bored and tapped and has a trip rod 141 threaded therein and held in adjusted position by a lock nut 142.

The arrangement is such that, when slides 6 and 17 are in their upper positions and the tail 39 of a breach is inserted into bushing 122, the tapered end of tail 39 will swing lever 125 upon pin 126 and permit tail 39 to be moved upwarduntil cannelure 38 registers with opening 123. Then spring 129 and plunger 12% will swing the right end of lever 125 downward to lock the breach to socket 23.

After a broach has been locked in socket 23 downward movement of slide 17 to the end of its stroke will cause the nose .of the breach to be inserted into a tool puller 24, a slight downward movement of slide 6 will cause the nose of the broach to be locked in puller 24, slides 6 and 17 will move downward together until slide 6 reaches a given, point at which time the greater part of the broaching operation will have been completed, and then motors 18-19 will be energized and will move slide 17 upward relatively to slide 6 as previously explained.

Just before motors 18-19 are energized, downward movement of cam rod 136 is stopped by rod 141 engaging a suitable abutment such as work support 4. As slide 17 continues downward, roller 133 will ride up the inclined part 143 of cam track 135 and cause lever 130 to swing locking lever 125, out of cannelure 33, thereby releasing the broach so that motors 1819 can move slide17 upward relatively to slide 6.

Duringtbetimc that opposite ends of the breach are engaged by socket 23 and puller 24, tension may be maintained upon the broach by subjecting the lower faces 8 of pistons 19 to a low pressure. This may be accomplished by connecting the lower ends of cylinders 18 to gear pump 72 such as by connecting gear pump supply channel 73 to channel thru a check valve 144 and providing a shut-off valve 145 in channel 73 between check valve 144 and pump 72 as indicated in Fig. 9. Then by opening valve 145 slightly, gear pump pressure will extend into the lower ends of cylinders 18 but flow of gear pump liquid into cylinders 18 when pistons 19 are moving upward and when the lower ends of cylinders 13 are connected to exhaust is kept at a very low rate by valve 145. It is obvious that the rate at which gear pump liquid can flow to cylinders 18 could be limited by a choke inserted into channel 73 in which case valve 145 could be fully opened.

, THE ELECTRIC CIRCUIT Electric current for energizing the several solenoidsis supplied from power lines L1 and L2 as indicated in FigflS which shows only so much of the electric circuit as is necessary to an understanding of the operation of the machine during a semi-automatic cycle but in practice the circuit includes suitable means for connecting lines L1 and L2 to a source of power, means for effecting movement of slides 6 and 17 upward or downward independently and selectively, means for effecting full automatic operation of the machine, suitable safety means such as one or more stop switches and additional starting switches which require that the operator use both hands to start the machine, and a selector switch for selecting between manual control, automatic operation and semiautomatic operation of the machine.

Solenoids S1 and S2 are controlled, respectively, by two magnetic switches or contactors C1 and C2. As indicated in Fig. 16, contactor C1 includes a magnet in and two switches a and b while contactor C2 includes a magnet m and three switches a, b and c. As indicated in Fig. 15, solenoid S1 has one end of its winding connected directly to line L1 and the other end of itswinding connected to line L2 through switch Cl solenoid 52 has one end of its winding connected directly to line L1 and the other end of its winding connected to line-L2 through switch C2 and solenoid S3 has one, end of its winding connected directly to line L1 and the other end of its winding connected to line L2 through pressure switch PS1.

Solenoids S4 and S5 are controlled, respectively, by two magnetic switches or contactors C3 and C4 each of which includes a magnet mand two switches a and b as indicated in Fig. l6. Solenoid S4 has one end of its winding connected directly to line L1 and the other end of its winding connected to line L2 through switch C3 while solenoid S5 has one end of its winding connected directly to line L1 and the other end of its winding connected to line L2 through switch C4 as indicated in Fig. 15.

Contactor C1 is controlled in part by a limitswitch LS1 and in part by a limit switch LS2. As indicated in Fig. 9, limit switch LS1 is a single normally closed switch which is adapted to be operated at the end of the down stroke of slide 6 by an actuator carried by slide 6 while limit switch LS2 is a multiple switch having three normally open contacts or individual switches a, b and c which are adapted to be closed by an actuator 151 carried by slide 17. As indicated in Fig. 15, magnet C1 of contactor C1 has one end of its winding connected directly to line L1 and the other end of its winding connected to one terminal of switch LS1 the other terminal of which is connected to one terminal of switch C1 and to one terminal of switch LSZ The other terminals of switches Cl and LS2 are connected to line L2.

Contactor C2 is controlled in part by a manually operable starting switch SS1 and in part by a double acting limit switch LS3. As indicated in Fig. 9, limit switch LS3 has two contacts or individual switches a and b and is spring biased to a position in which its switch a is Open and its switch b is closed but, when slide 6 moves to itsupper limit, an actuator 152 carried by slide.6'closes switch a and opens switch b. As indicated in Fig. 15, magnet C2 has one end of its winding connected directly to line L1 and the other end of itswinding connected. to one terminal of each of switchesSSl and C2" theother terminals of which are connected to one terminal of switch LS3 which has its other terminal connected to line L2.

Contactor C3 is controlled in part by each of a menually operable starting switchv SS2, contactor C2, limit switch LS2 and pressure switch PS2 which as indicated in Big. 9 includes two normally closed individual switches a' and b. As indicated in Fig. 15, magnet 03* has one end of its winding connected directly to line L1 and the other end of its winding connected to one terminal .of each of switches SS2, C3 and 02. The otherterminal of switch C2 is connected directly to line L2. The other terminals of switches SS2 and C3 are both connected to one terminal of each of switches LS2 and PS2 the other terminals of which are connected to lineL2.

Contactor C4 is controlled in part by each of pressure switch PS2, limit switch LS2, a'limit switch LS4 and a contactor C5 which as indicated in Fig. 16 includes a magnet m and two switches a and b. As indicated in Fig. 9, limit switch LS4 is adapted to be closed momentarily at a given pointin the down stroke of slide 6 by an actuator 153 carried by slide 6. It is not closed during the up stroke of slide 6.

As indicated in Fig. 15, magnet C4 hasoneend of its winding connected directly to line L1 and the other end of its winding connectedto one terminal of each of switches 05', C 3 and LS4 the other terminals ofwhiCh are connected to one terminal of each ofswitches LS2 and 1 52 which have their other terminals connected, to line L2.

Contactor C5 is controlled in part by limit switches LS2 and LS3 and in part by pressure switch PS2. As indicated in Fig. 15, magnet CS has one end of its winding connected directly to line L1 and the other end of. its winding connected to one terminal of switch LS3. the other terminal of which is connected to one terminal of each of switches C5 and LS2. The other terminal of switch LS2 is connected to line L2. The other terminal of switch C5 is connected to one terminal of switch PS2 the other terminal of which is connected to line L2.

Operation Referring now primarily to Figs. 9 and and assuming that work to be broached is arranged upon support 4 and that a broaching tool is supported at its upper end in each of sockets 23, the machine will operateas follows: With the parts in the positions shown and with pumps P1 and P2 running, pump P1 will be at zero displace.- ment so that no liquid is delivered thereby, pump P2 will be bypassed through valve 95, actuator-152 will be holding switch LS3 closed and switch LS3 open, slide 6 will be supported by liquid trapped in cylinder '7 by foot valve 80 and slide 17 will be supported by liquid trapped in cylinders 18 by relief valve 114.

When starting switch SS2 is closed, it will establish a circuit (Li'C3 SS2-PS2 L2) to energize magnet C3 and cause contactor C3 to close its switches In and b. Closing switch C3 will establish a holding circuit to-keep magnet C3 energized when starting switch SS2 is released. Closing switch C3 will establish a circuit to energize solenoid S4 which will shift valve member 98 to the position shown in Fig. 11 and then the liquid discharged by pump P2 will flow to the upper ends. t cylinders 18 and cause pistons 19 to move slide 17downward as previously explained.

As slide 17 moves downward, the lower ends of the broaches carried by sockets 23 will pass through the work 10 and into tool pullers 24. Just before slide 12 reaches the end of' its down stroke relatively toslide 6; actuator 151-will operate limit switch LS2 to-close its switches a and b. Closing switch LS2" will establish a holding circuit around switch PS2 Closing switch LS2 will establish a circuit (L1-C1 -LS1-LS2'-L2) to energize magnet Cl Inst after actuator 151 operates limit switch LS2, pistons 19 willstall against the lower-ends of cylinders 18 which will cause the pressure created by pump P2 to rise sufficiently to open relief valve 107 and cause pressure switch PS2 to open but the circuit through magnet 63" is maintained by limit switch LS2.

Energizing magnet Cl will cause contactor C1 to close its switches a and b. Closing-switch C1 will establish a circuit to keep magnet C1 energized when switch LS2 opens. Closing switch C1 will establish a circuit to energize solenoid S1 and thereby cause pump P1 to discharge liquid which will flow through channel .68,- move plunger of differential valve 84 to the position shown in Fig. 10 and then create in channel 88 a pressurewhich will cause pressure switch PS1 to close and establish a circuit to energize solenoid S3 which will cause foot valve '80 to open at a low pressure and then liquid will :flOW to the upper end of cylinder 7 and cause piston 8 to move slide 6 downward as previously explained.

As soon as slide 6 starts downward, actuator 152 will release limit switch LS3 which will open its switch .a and close switch b to condition the circuit for subsequent operation. -As slide 6 movesdownward, tool pullers 24 will move out of contact with abutment 54 which will permit pullers 24 to lock the breaches to slide 6. Just after the broaches have been locked in pullers 24, .actuator 151 will move below limit switch LS2 and permit switches LS2 and LS2. to open. Opening switch LSZ has no efiect because the circuit throughmagnet C1 is maintained by switch Cl .Opening switch LS2 .will

, broaching operation. At a given point in the down stroke of 'broach 6 such as whensockets 23 have approached to a point close to the work, actuator 153 will; close limit switch LS4 momentarily to establish a .circuit (LL-LS4- PS2 L2) to energize magnet Ol avhich will cause con: tactor C4 to close its switches a and b. Closing switch C4 will establish .a circuit to keep magnet C4 energized when limit switchLS4 opens. Closing switch 041 will establish a circuit to energize solenoid. S5 which will shiftwalve member 98 into the position shown in Fig. 12 and then the 'liquid'discharged by pump P1 will flow to the lower ends .of cylinders 18 and .cause pistons 19 (to move slide '17 to its upper position relative to slide .6 as previously explained. Switch LS4 will open as soon as actuator 153 has moved below it but the circuit through magnet C4 1 will be maintained by a switch C4 until pistonsx19 stall against the upper ends of cylinders 18 which will cause the pressure created by pump P2 to rise and open pressure switch PS2.

Opening switch PS2- will break the'circuit through magnet CM and permit contactor'C4 to open and dc energize solenoidSS which will permit valve member 98 to be returned to its neutral position and bypass pump P2, thereby causing pump pressure to drop and permit pressure sWitchPSZ to close. Slide '6 will continue dpwnward until actuator opens limit switch LS1 to break the circuit through magnet C1 and permit contactor C1 to open and deenergize solenoid S1 which will cause the displacement of pump 1 1 P1 to be reduced to zero, thereby deenergizing motor 7-8. Reducing the displacement of pump P1 to zero will cause pump pressure in channel 88 to drop and permit pressure switch PS1 to open and deenergize solenoid S3 which will cause foot valve 80 to close and prevent further downward movement of slide 6.

After the work has been removed from support 4, an up stroke of slide 6 may be initiated by closing starting switch SS1 to establish a circuit (L1-C2 SS1-LS3 L2) to energize magnet C? which will cause contactor C2 to close its switches a, b and 0. Closing switch C2 will establish holding circuit to keep magnet C2 energized when starting switch SS1 is released. Closing switch C2 will establish a circuit to energize solenoid S2. Closing switch C2 wilt establish a circuit (L1C3 -C2-L2) to energize magnet C3 which will cause contactor C3 to close its switches a and b. Closing switch C3 will establish a circuit to energize solenoid S4. Closing switch C3 will have no effect at this time.

Energizing solenoid S2 will cause pump P1 to discharge liquid into channel 64 and the liquid will move differential valve plunger 90 to the position shown in Fig. 9 but it cannot enter either end of cylinder 7 because foot valve 80 is closed. Therefore, pump pressure will rise and close pressure switch PS1 to cause solenoid S3 to be energized and to condition foot valve 80 so that it will open at a low pressure as previously explained. The liquid discharged by pump P1 will then flow through channel 64, foot valve 80 and channel 81 to the lower end of cylinder 7 and cause piston 8 to move slide 6 upward and to eject liquid from the upper end of cylinder 7 through channel 88, differential valve 84, channel 64, foot valve 89 and channel 81 to the lower end of cylinder 7 so that slide 6 is moved upward at high speed. As slide 6 starts upward, actuator 150 will permit limit switch LS1 to close but no circuit will be establishe. because switch C1 is open.

Energizing solenoid S4 will cause it to shift valve member 98 to the position shown in Fig. 11 and thereby cause pistons 19 to move slide 17 downward relatively to slide 6 as previously explained.

Slides 6 and 17 are started moving simultaneously but slide 6 moves at such a high speed that it will have moved the upper ends of the breaches well above support 4 before slide 17 completes its stroke. As slide 17 approaches the end of its down stroke relatively to slide 6, sockets 23 will engage the upper ends of the breaches and imme diately thereafter pistons 19 will stall against the lower ends of cylinders 18 and then the pressure created by pump P2 will rise and cause pressure switch PS2 to open which will cause contactor C3 to open, solenoid S4 to be dcenergized and valve member 98 to return to neutral to bypass pump P2 as previously explained.

After slide 17 has completed its stroke, slides 6 and 17 will move upward as a unit. As slide 6 approaches its upper limit. actuator 151 will cause limit switch LS2 to close its switch LS2 and immediately thereafter actuator 152 will cause limit switch LS3 to break the circuit through magnet C2 and. to establish a circuit (Ll-C" LS3*'LS2-L2) to energize magnet C5 Breaking the circuit through magnet C2 will cause contactor C2 to 'open switches a, b and c. Opening switches C2 and C2 will have no effect at this time. Opening switch C2 will deenergize solenoid S2 which will cause the displacement of pump P1 to be reduced to zero with a resultant drop in pressure which will cause pressure switch. PS1 to open and deenergize solenoid S3 which will cause foot valve 80 to close and support piston 8 in its upper position.

Energizing magnet C5 will cause contacter C5 to close its switches a and [1. Closing switch CS will keep magnet .CS'" energized when switch LS2 opens. Closing switch 12 C5 will establisha circuit (L1-C4 -C5 -PS2-L2) to energize magnet C t and cause contactor C4 to close its switches a and b. Closing switch C4 will have no effect at this time. Closing switch C4 will establish a circuit to energize solenoid S5 which will cause valve member 98 to shift to the position shown in Fig. 12 and pistons 19 to move slide 17 upward relatively to slide 6 as previously explained. After slide 17 moved a short distance upward relatively to slide 6, actuator 151 will disengage limit switch LS2 which will open its switch LS2 but the circuit through magnet CS will be maintained by switch C5". N

Slide 17 will continue upward until pistons 19 stall against the upper ends of cylinders 13 which will cause the pressure created by pump P2 to rise and open pressure switch PS2 which will deenergize magnets 04' and C5 and permit contactors C4 and C5 to open their switches a and b. Opening switches C4 C5 and C5 will prevent magnets (34 and CS from being re-encrgized when pressure switch PS2 closes. Opening switch C4 will deenergize solenoid S5 which will permit valve member 98 to return to neutral and bypass pump P2, thereby causing pump pressure to drop and pressure switch PS2 to close as previously explained.

The parts will then be in their original positions and a second cycle of operations may be initiated by closing starting switch SS2.

The breaching machine disclosed herein may be modified in various ways without departing from the scope of the invention which is hereby claimed as follows:

1. In a broaohing machine for reciprocating a breach through work, a frame, a main slide mounted for sliding movement on said frame, a tool handling sub-slide mounted for sliding movement on said main slide, means mounted on said main slide for gripping one end of a broach, means mounted on said sub-slide for gripping the other end of a breach, power means mounted on said frame and connected to said main slide for recipro eating the same and said sub-slide as a unit in a broaching operation, power means mounted on said main slide and connected to said sub-slide for creating a tension on said breach during breaching and for moving said subslide relative to said main slide a sufficient distance to facilitate placement and removal of said breach through said work.

2. In a breaching machine for reciprocating a breach through work, a frame, a main slide mounted for slitting movement on said frame, a tool handling sub-slide mounted for sliding movement on said main slide, means mounted on said main slide for gripping one end of a breach, means mounted on said sub-slide for gripping the other end of a breach, power means mounted on said frame and connected to said main slide for reciprocating the same and said sub-slide as a unit. in a breaching operation, a fluid motor mounted on said main slide and connected to said sub'slidc for moving said sub-slide rela tive to said main slide a sutficicnt distance to facilitate placement and removal of said breach through said work.

References Cited in the file of this patent UNITED STATES PATENTS 1,937,12l Lapointe 2. Nov. 28, l933 2,135,157 West Nov. 1, 1938 2,135,861 Thompson Nov. 8, 1933 2,253,303 Lapointe Aug. l9, 194! 2,315,476 Greene Mar. 30, 1943 2,343,420 Podesta Mar. 7, 1944 2,372,823 Gotberg Apr. 3, 1945 FOREIGN PATENTS 440,852 Great Britain Jan. 7, 1936 

